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How Does the Green Light Work on the Front of Cabin?

Sometimes, you see the three green lights which are attached to the front of the cabin of the large Japanese truck. (I mention the green lights in the picture below)

This light illuminates green, sometimes only one is lit up, and another time two or all of lights may be lit up, depending on the time you see it.

Have you ever wondered what meanings the light has?I didn’t know that this light has a certain meaning, and just thought this is a decoration or has a role to notify people that the truck is coming by lighting up.

This is just a small trivia of trucks, and may not be the most useful knowledge. However, very few people know this even though they are Japanese truck drivers, so if you like Japanese trucks, it may makes you fun.

FUNCTION

This light is to inform surrounding vehicles that the speed of the truck running from the front, and it raised the attention to the truck for safety reasons. So, it was called speed display light or device.

As seen from oncoming vehicle side, it lights in the order of 1) the right, 2) the left, and 3) the middle light. One light means the speed less than 40 km / hour, two indicates the speed between 40 km / hour and less than 60 km / hour, and three does more than 60 km / hour.

HISTORY (Why was this light attached?)It was in 1967 that the obligation of this green light was stipulated by the Road Trucking Vehicle Law (The Japanese law applied to transportation vehicles). This obligation was subjected only largest trucks that gross weight was more than 11 tons, the loading weight was more than 6.5 tons.

The reason why this obligation was applied only to large trucks could be due to considering the situation of minor accidents by heavy trucks in 1967 when this duty was prescribed.

In Japan, we rarely see the trucks which attach this green light recently on public roads.

It is because of the partial revision of the safety standards of road transport vehicles, and that made it duty to attach the green lights abolished in 2001. The law description changed from “the truck maker must attach the green light” to “they can attach that light”, or “they are accepted to attach one”; changed the obligation to arbitrarily.

The background of this safety standards revision was that while improving the road infrastructure, the role of the green light has become less important from the viewpoint of preventing the vehicle accidents compared to the traffic situation in 1967 when the standards was constituted.

What kind of correspondence did the manufacturers of the truck take due to the abolishment of the obligation to install the speed display device?

In the cases of HINO and ISUZU, both manufactures have removed the green light from the trucks manufactured since the abolishment of the duty in 2001.

While removing the green light, it starts the largest trucks are attached speed limiter device that controls the speed if the trucks run at over 90 km / hour. This is for making people have an attention to the speed when driving along highways.

With the changing regulation or the situations of transportation, trucks have constantly changed their model.You will have fun to find more changes comparing the previous models and current models.